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Biomedical subjects

D L Rosenfeld

Publications and source records attributed to D L Rosenfeld.

At least 19 recordsLinked to original sources
PubMed2001

Topography of cerebral white-matter disease of prematurity studied prospectively in 1607 very-low-birthweight infants.

The objective of this study was to evaluate to what extent (1) the characteristics of localization, distribution, and size of echodense and echolucent abnormalities enable individuals to be designated as having either periventricular hemorrhagic infarction or periventricular leukomalacia and (2) the characteristics of periventricular hemorrhagic infarction and periventricular leukomalacia are independent occurrences. The population for this study consisted of 1607 infants with birthweights of 500 to 1500 g, born between January 1991 and December 1993, who had at least one cranial ultrasound scan read independently by at least two ultrasonographers. The ultrasound data collection form diagrammed six standard coronal views. The cerebrum was divided into 17 zones in each hemisphere. All abnormalities were described as being echodense or echolucent and were classified on the basis of their size, laterality, location, and evolution. Eight percent (134/1607) of infants had at least one white-matter abnormality. The prevalence of white-matter disease decreased with increasing gestational age. Most abnormalities were small or medium sized and unilateral; only large echodensities tended to be bilateral and asymmetric. Large abnormalities, whether echodense or echolucent, were more likely than smaller abnormalities to be widespread, and the extent of cerebral involvement was independent of whether abnormalities were unilateral or bilateral. Large abnormalities were relatively more likely than small abnormalities to involve anterior planes. Small abnormalities, whether echodense or echolucent, or whether unilateral or bilateral, preferentially occurred near the trigone. Using the characteristics of location, size, and laterality/symmetry, we were able to allocate only 53% of infants with white-matter abnormalities to periventricular hemorrhagic infarction or periventricular leukomalacia. Assuming that periventricular leukomalacia and periventricular hemorrhagic infarction are independent and do not share risk factors, and that each occurs in approximately 5% of infants, we would have expected 0.25%, or about 4 individuals, to have abnormalities with characteristics of both periventricular leukomalacia and periventricular hemorrhagic infarction, whereas we found 63 such infants. Most infants with white-matter disease could not be clearly designated as having periventricular hemorrhagic infarction or periventricular leukomalacia only. Periventricular hemorrhagic infarction contributes to the risk of periventricular leukomalacia occurrence, or the two sorts of abnormalities share common risk antecedent factors. The descriptive term echodense or echolucent and the generic term white-matter disease of prematurity should be used instead of periventricular leukomalacia or periventricular hemorrhagic infarction when referring to sonographically defined white-matter abnormalities.

Brain Mapping↗
PubMed2001

Uterus didelphys with obstructed hemivagina and ipsilateral renal agenesis. A case report.

BACKGROUND: Uterus didelphys with obstructed hemivagina and ipsilateral renal agenesis usually presents after menarche with progressive abdominal pain during menses secondary to hematocolpos. We describe a case with the unique presentation of rectal pain and constipation. CASE: A 13-year-old girl presented to the emergency department complaining of lower abdominal and rectal pain and constipation of two weeks' duration. Pelvic ultrasound, physical examination and laparoscopic findings established a diagnosis of hematometracolpos secondary to uterus didelphys with unilateral imperforate hemivagina. An incision in the vaginal septum allowed drainage of the hematocolpos, providing relief of the patient's symptoms. CONCLUSION: Uterus didelphys with unilateral imperforate hemivagina and ipsilateral renal agenesis may present with apparent gastrointestinal symptoms. With increased awareness of this problem, timely diagnosis may be achieved.

Adolescent↗
PubMed1999

Development of a life-threatening anaphylactoid reaction following administration of ioversol in a child.

We report for the first time the case of a 3-year-old girl who developed a severe anaphylactoid reaction following the administration of the nonionic, low osmolar intravenous radiographic contrast agent ioversol. Severe reactions to ioversol have rarely been reported in adult patients and to our knowledge never in children. Health care providers managing children who may require radiologic imaging studies with ioversol should be aware of the potential complications of this radiographic contrast agent.

Anaphylaxis↗
PubMed1999

Bilateral smooth-muscle tumors of the adrenals in a child with AIDS.

We report a case of bilateral smooth muscle tumors (SMT) involving the adrenal glands in an 11-year-old female with acquired immunodeficiency syndrome (AIDS). The SMT of the right adrenal gland extended into the inferior vena cava, producing a tumor thrombus.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Acrobeads test as a predictor of fertilization in vitro.

PROBLEM: To determine whether the results of the Acrobeads test, which measures the expression of the complement regulator molecule CD46 on the inner acrosomal membrane following the acrosome reaction, accurately identifies semen specimens that will exhibit reduced or failed fertilization following conventional IVF insemination. METHOD: The Acrobeads test was performed on semen specimens from 97 consecutive patients preparing to undergo an IVF cycle utilizing a standardized insemination protocol. Motile sperm populations were examined at 6 h and 24 h post-isolation for sperm-bead agglutination. Results of the Acrobeads test were compared to that of TRITC-PSA staining in matched specimens to directly measure the spontaneous loss of acrosome content. The percentages of TRITC-PSA-negative sperm were determined in freshly isolated motile populations and in duplicate aliquots incubated 18 to 20 h under sperm capacitating conditions. The relationship between the results of both analyses estimating spontaneous acrosome reactions and the rate of fertilization of metaphase II oocytes was examined. RESULTS: The Acrobeads score did not correlate significantly with the rate of fertilization by insemination at 6 h or at 24 h. The negative predictive value of this test was 21.4%. There was no correlation between the Acrobeads score and the percentage of sperm undergoing a spontaneous acrosome reaction as detected by TRITC-PSA labeling. In contrast, the increment increase in the percentage of spontaneous acrosome reactions as quantified by TRITC-PSA staining was correlated with the fertilization rate. CONCLUSIONS: Contrary to previous reports, our prospective, double-blinded study failed to demonstrate that the Acrobeads test can accurately predict fertilization outcome in IVF. Therefore, the routine use of this test to screen patients prior to an IVF cycle in order to select appropriate treatment (i.e., ICSI) cannot be recommended.

Acrosome↗
PubMed1996

Jugular thrombophlebitis complicating bacterial pharyngitis (Lemierre's syndrome).

Lemierre s syndrome is a rare syndrome caused by Fusobacterium necrophorum, a gram-negative anaerobic organism that normally inhabits the oropharynx. The syndrome follows primary oropharyngeal infection and affects previously healthy adolescents in a characteristic manner with fatal results if left untreated. The authors present two cases seen at their institution and discuss the clinical and radiologic features of the syndrome, along with considerations for patient management.

Adolescent↗
PubMed1996

Intracranial route of a cervical neuroblastoma through skull base foramina.

A case of primary cervical neuroblastoma gaining access to the cerebellopontine angle via direct perineural spread is described. MRI effectively delineated soft tissues, while CT demonstrated tumor calcifications and the integrity of adjacent bones. Both imaging modalities were beneficial in predicting the unique histology and pattern of disease confirmed at surgery.

Cerebellar Neoplasms↗
PubMed1995

Transtentorial herniation of the fourth ventricle.

Transtentorial herniation (TTH) of the fourth ventricle is the result of a progressive enlargement of an isolated fourth ventricle which herniates through the tentorial incisure into the middle cranial fossa. The characteristic CT-MR and neurosonographic findings are described.

Cerebral Hemorrhage↗
PubMed1994

Serial renal sonographic evaluation of patients with Lesch-Nyhan syndrome.

The objective of this study was to review sequential renal sonograms of patients with Lesch-Nyhan syndrome obtained over several years to determine different sonographic patterns, the alterations in the patterns occurring over time and the relationship to management. Additional objectives were to evaluate the size of the kidneys, and to correlate the metabolic constituents of calculi with the therapeutic regimens and with the renal sonographic patterns. Serial sonograms of six patients with Lesch-Nyhan syndrome were reviewed for periods varying between 2 and 7 years with a mean of 4 years. The ages of the patients at the conclusion of the study were between 10 and 22 years. Three patterns of abnormal echogenicity were found; a punctate increase in echogenicity in the renal medullary pyramids, a diffuse increase in medullary pyramid echogenicity, and a pattern of increased echogenicity in the collecting system. These patterns were progressive but did not alternate on sequential scans, regardless of increasing or constant therapy. Analysis of calculi suggested patients were precipitating various metabolites concurrently; the incidence of metabolites appeared to be unrelated to therapy. Those patients with shadowing opacities, whether in the renal medulla or collecting system, were more likely to develop renal colic. Renal dimensions were small with renal function remaining normal.

Adolescent↗
PubMed1994

The effect of calcium ion channel blockers on sperm fertilization potential.

OBJECTIVE: To evaluate the effects of calcium ion (Ca2+) channel blockers on male fertility potential. DESIGN: A case comparison of the surface expression of mannose-ligand receptors on motile spermatozoa from 10 known fertile males and from 10 normospermic men taking Ca2+ channel blockers who were seeking infertility treatment. Examination of the effects of in vitro exposure of sperm from fertile donors (n = 14) to antihypertensive medications. SETTING: Patients from a successful university hospital-based IVF-assisted reproductive technology program and from a male urology private practice. INTERVENTIONS: Prescription of alternate hypotensive medications for four male patients; cholesterol loading and unloading in vitro of fertile donor sperm. MAIN OUTCOME MEASURES: Motile sperm were tested for their ability to bind fluorescein isothiocyanate-labeled, mannosylated bovine serum albumin as an index of the surface expression of mannose-ligand receptors associated with fertility potential. Acrosome status was simultaneously evaluated by fluorescence microscopy with rhodamine-labeled Pisum sativum lectin. Sperm were assayed before and after an 18-hour or 3-day incubation under capacitating conditions in vitro. RESULTS: Motile spermatozoa of normospermic men taking calcium antagonists for hypertension control do not express head-directed mannose-ligand receptors at high frequency, nor do they undergo spontaneous acrosome loss. Unexpectedly, mannose-ligand receptor translocation from the subplasmalemmal space over the acrosome to the sperm surface and aggregation over the equatorial-postacrosomal regions occurred in acrosome-intact sperm. This differs from fertile controls in whom receptor translocation to the equatorial-postacrosomal segment is coupled with the acrosome reaction (AR). Discontinuation of calcium antagonists results in complete recovery of parameters associated with sperm fertilizing potential: time-dependent increases in the percentages of spermatozoa exhibiting surface mannose-ligand binding and spontaneous ARs in vitro. The effects of in vivo administration of calcium antagonists is mimicked in control fertile donor sperm by inclusion of a Ca2+ channel blocker in the media employed during capacitating incubations. CONCLUSIONS: Therapeutic administrations of calcium antagonists for hypertension control cause reversible male infertility associated with an IVF failure. A mechanism of inhibition of sperm fertilizing potential through insertion of lipophilic calcium ion antagonists into the lipid bilayer of the sperm plasma membrane is consistent with our in vitro studies.

Acrosome↗
PubMed1993

Head-specific mannose-ligand receptor expression in human spermatozoa is dependent on capacitation-associated membrane cholesterol loss.

D-Mannose binding lectins appear on the human sperm head following in-vitro incubation under capacitating conditions. Surface expression of lectin is dependent on reduction of the sterol content of sperm membranes. Mannose-specific lectin distribution over the head differs in acrosome-intact and acrosome-reacted spermatozoa. Sugar competition experiments show that mannose is the only saccharide competitive with D-mannosylated albumin binding and that free mannose induces an acrosome reaction in capacitated spermatozoa. A total of 183 men with normozoospermic semen parameters were screened for the ability of their spermatozoa to bind fluorescein isothiocyanate (FITC)-labelled mannosylated albumins, before and after incubation in vitro. The spermatozoa from 176 men 'responded' to incubation by exhibiting time-dependent increases in head-directed mannosylated albumin binding, accompanied by increases in the percentage of spermatozoa showing spontaneous acrosome loss. Motile spermatozoa from the remaining seven men failed to express mannose-lectin binding activity after 18 h of incubation and only low percentages of their spermatozoa showed spontaneous acrosome loss. These seven men were classified as 'non-responders'. The relative amounts of non-esterified cholesterol in the sperm membranes of the responder and non-responder males were analysed by gas-liquid chromatography. Responder spermatozoa showed decreases in free cholesterol content whereas non-responder spermatozoa exhibited either no decrease or increases in relative free cholesterol per cell. Fresh swim-up spermatozoa contain sub-plasma membrane stores of mannose lectins which are revealed by FITC-mannosylated albumin labelling before and after removal of the plasma membrane by vortexing. In contrast, the mannose-lectin binding activity of capacitated spermatozoa is entirely limited to the sperm surface. Western blots of proteins isolated from sperm plasma membranes after capacitation revealed two molecular species reactive with polyclonal antibodies against human macrophage mannose receptors. A model is proposed for the molecular mechanism whereby mannose lectins are transposed from sub-plasma membrane sites to an integral membrane position as a consequence of the loss of cholesterol from the sperm membrane.

Cell Membrane↗
PubMed1993

Fertilization potential in vitro is correlated with head-specific mannose-ligand receptor expression, acrosome status and membrane cholesterol content.

Normozoospermic men who do not fertilize human eggs in vitro constitute a clearly identifiable class of occult male factor infertility. We have studied the relationships between in-vitro fertilization (IVF) outcomes and the appearance of sperm surface mannose lectin/zona pellucida ligand activity measured by the binding of fluorescein isothiocyanate (FITC)-labelled mannosylated albumin. Of 338 semen specimens with normal profiles, 10 (2.96%) failed to fertilize in vitro (IVF-). Motile spermatozoa from six of these were analysed retrospectively for zona ligand binding activity on the sperm head in relation to acrosome status and the free cholesterol content of their plasma membrane. IVF+ males and fertile donors served as controls. The six IVF- occult male factor cases were distinguished from controls by their failure to show time-dependent increases in the percentage of spermatozoa exhibiting head-directed mannose ligand activity, by the slow loss or apparent increase in membrane cholesterol and by the absence of spontaneous and/or mannose-induced acrosome exocytosis.

Acrosome↗
PubMed1993

Correlations between serum oestradiol level on day of HCG and speed of embryonic development in in-vitro fertilization.

The number of embryos transferred, ease of embryo transfer, and rate of embryo cleavage are significant factors affecting the success of IVF. High levels of oestradiol occurring when HCG is given may reduce implantation and pregnancy rates. A discrepancy between the stage of embryonic development and the phase of endometrial maturation at embryo transfer may be responsible for IVF failure in some cases.

Chorionic Gonadotropin↗